Fastener driving apparatus



y 1966 R. H. DOYLE ETAL 3,253,760

FASTENER DRIVING APPARATUS 7 Filed Jan. 29, 1964 3 Sheets-Sheet 1 Fwd/120 DOYLE- AA/D AzM/A/ F/EDLE/Z I ATTOEA/E-YS- y 31, 1966 R. H. DOYLE ETAL 3,253,760

FASTENER DRIVING APPARATUS Filed Jan. 29, 1964 3 Sheets-Sheet 2 y 1966 R. H. DOYLE ETAL 3,253,760

FASTENER DRIVING APPARATUS Filed Jan. 29, 1964 3 Sheets-Sheet I5 o Q I 200 4. 36 as Mg M 4 as ATTOkA/EYS.

United States Patent 3,253,760 FASTENER DRIVING APPARATU S Richard H. Doyle, Mount Prospect, and Armin Fledler,

Chicago, lfll., assignors to Fastener Corporatron, Franklin Park, 111., a corporation of Illinois Filed Jan. 29, 1964, Ser. No. 340,863 Claims. (Cl. 227-120) This invention relates to a fastener driving apparatus and, more particularly, -to a new and improved pneurnatically operated tool for driving large fasteners.

The demonstrated desirability of pneumatically d r1v ng staples and smaller fasteners, such as T-nails or finishing nails, has led to a demand for pneumatic tools capable of driving and setting a greater range of fasteners including common or cooler nails with lengths up to two and one-half inches. In many instances, the design of new tools capable of driving nails has followed the path of merely increasing the powerof the tool available durmg the driving stroke and of making the necessary modifications in the size and configurations of the drive track, driver element, and magazine assembly. The power available is commonly i-ncreased by increasing the diameter and stroke of the piston. There are practical limits, however, to the increases in the size and weight of the tool inherent in increasing piston diameter and stroke that can be tolerated. In addition, the design of a magazine assembly and the selection of a method of feeding larger fasteners, particularly nails with a full round head, that will provide adequate magazine capacity without unduly increasing the size and weight of the portable tool presents a number of problems.

Accordingly, one object of. the present invention is to provide a new and improved fastener driving apparatus.

Another object is to provide a fastener driving tool capable of driving'large fasteners such as nails with a full round head.

Another object is to provide a fastener driving tool including a new and improved cylinder exhaust system.

Another object is to provide a pneumatically operated tool including a cylinder exhaust system offset from the main valve for the open end of the cylinder to reduce the height and size of the tool. 1

A further object is to provide a fastener driving tool including a magazine assembly offset at an acute angle from a rearwardly extending handle for the tool.

Another object is to provide a fastener driving tool including new and improved means for securing a magazine assembly to the tool housing.

A further object is to provide a fastener driving tool including a magazine assembly detachably mounted on the tool housing by means affording sliding and pivotal movement.

A further object is to provide a fastener driving tool including a new and improved magazine assembly.

Another object is to provide a magazine assembly for a fastener driving tool in which the fastener pusher carries resilient bumper means.

Another object is to provide a magazine assembly for a fastener driving tool in which the fastener supporting rails are so formed as to provide a housing for receiving a resilient biasing means for a pusher.

In accordance with these and many other objects, an embodiment of the invention comprises a pneumatically operated tool for driving round-headed nails comprising a portable housing having both a vertically extending head portion and a rearwardly extending handle. A portion of the head and the handle portions are hollow and provide a reservoir in which is disposed a movable cylinder having an open end normally sealed by a main valve carried on a closure cap sealing an opening in the upper end of the head of the housing. Control means actuated by Patented May 31, 1966 a manual trigger and means actuated by engagement with a workpiece control shifting movement of the cylinder into and out of engagement with the main valve to control the admission of air for driving a fastener driving means including both a piston slidable within the cylinder and a depending driver blade or element that is also slidably received within the drive track formed in a nosepiece carried on the lower end of the head portion. A piston return valve assembly carried on the cylinder is rendered effective in dependence on the pressure within the upper end of the cylinder to supply compressed air below the piston to 'retract the piston following the completion of a driving stroke.

To obtain the power necessary to drive larger fastenerssuch as nails, the fastener driving means includes a piston of increased diameter and, in some instances, a lengthened stroke. This tends to increase the height and size of the head portion of the housing. The increase in the height of the head portion can be oflset to a substantial degree by removing the exhaust valve system commonly disposed directly above the open end of the cylinder to permit a corresponding reduction in the height of the head structure above the cylinder. In accordance with one feature of the present invention, the exhaust valve system includes an exhaust valve controlling a flow of air from the open end of the cylinder to the atmosphere over an exhaust passage. This exhaust valve includes a piston portion continuously supplied with pressurized fluid from the reservoir for biasing the exhaust valve to a closed condition. However, the exhaust valve also includes an operator element engaged by the cylinder in a position offset radially from the cylinder which maintains the exhaust valve in an open condition when the cylinder is assembly remains in a closed condition until the cylinder is restored to its normal position at the conclusion of the driving stroke to again engage the operator and actuate the exhaust valve to an open condition.

Because of the physical space occupied by a strip of joined nails having full round heads, it-is necessary to somewhat increase the length of the magazine assembly without interfering with the operation of the other components of the tool and without unduly increasing the weight of the tool. In accordance with another feature of the present invention, this is accomplished by forming the staple magazine of a pair of elements defining a slot in which the shanks of the nails and a pusherare slidably mounted with the nails and pusher engaging the top edges of the rails. These rails are formed with outwardly projecting portions forming a cavity in which is disposed at resiliently biasing means connected to the pusher. Thus, a single pair of side rails not only provides a support and enclosure for the strip of nails but also encloses the biasring means without the need for the usual additional housing. To permit the magazine assembly to extend rearwardly for a greater length without interfering with the tool or its operation, both the magazine assembly and the nosepiece structure to which the magazine assembly is connected are angul-arly offset about the axis of \the cylinder to form an acute angle with the rearwardly extending handle of the housing. Damage to either the pusher or the structure defining the drive track is avoided by providing a resilient bumper on the pusher that serves to cushion the impact between the pusher and any engaged structures.

of the magazine assembly. Second structures formed on the magazine and the housing of the tool and spaced rearwardly from the nosepiece mount the magazine assembly for both sliding and pivotal movement. By releasing detachable connecting means at the forward end of the magazine, this assembly can be moved rearwardly and then swung downwardly to open not only the rear portion of the drive track in the nosepiece but also the forwar end of the magazine assembly.

Many other objects and embodiments of the present invention will become apparent from considering the following detailed description in conjunction with the drawings in which:

FIG. 1 is a side elevational view of a pneumatically operated fastener driving tool embodying the present invention;

FIG. 2 is a top plan view of the tool shown in FIG. 1;

FIG. 3 is an enlarged fragmentary sectional view taken along line 3-3 in FIG. 2 illustrating the pneumatic drive means for the tool;

FIG. 4 is an enlarged fragmentary sectional view taken along line 44 in FIG. 2 illustrating a nosepiece struc ture and a forward portion of a magazine assembly;

FIG. 5 is a sectional View taken along line 55 in FIG. 4;

FIG. 6 is a sectional view taken along line 6-6 in FIG. 5; and

FIG. 7 is an enlarged fragmentary sectional view taken along line 77 in FIG. 1.

Referring now more specifically to FIGS. 1 and 2 of the drawings, therein is illustrated a fastener driving tool which embodies the present invention and which is indicated generally as 10. The tool 10 comprises a housing '12 including a generally vertically extending head or forward portion 12a and a rearwardly extending hollow handle portion 12b. The interior of the head portion 12a and the handle 12b provides a reservoir 16 of pressurized fluid, such as compressed air, which is supplied to the tool by a flexible line connected to an inlet fitting 14. The drive system for the tool 10 includes a cylinder 18 (FIG. 3) movably mounted within the head portion 12a and having an open upper end that is adapted to be selectively connected to the reservoir 16. The cylinder 18 is normally biased to place its open upper end in engage ment with a main valve assembly 20 under the control of a safety or touch-trip valve assembly 22 and a manual valve assembly 24. A fastener driving assembly including a piston 26 slidably mounted within the cylinder 18 and having a depending driver element or blade 28 secured thereto is normally biased to a position adjacent the main valve 20 under the control of a piston return valve assembly indicated generally as 30. An exhaust valve assembly indicated generally as 32 for controlling the selective connection of the upper end of the cylinder 18 to the atmos phere is disposed on the housing 12 offset from the axis of the cylinder 18 to reduce the overall height of the tool 10.

When the tool 10 is to be operated, the safety valve assembly 22 and the manual valve assembly 24 are both operated to move the cylinder 18 downwardly away from the main valve assembly 20. As the cylinder 18 moves downwardly, the exhaust valve assembly 32 is closed and compressed air from the reservoir 16 enters the upper end of the cylinder 18 and drives the piston 26 and the connected driver blade 28 downwardly to engage and set a fastener or nail 34 (FIG. 4) supplied to a drive track 36 in a nosepiece or nosepiece structure 38 by a magazine assembly indicated generally as 40. When the cylinder 18 moves downwardly, a venting assembly indicated generally as 42 (FIG. 3) places the lower end of the cylinder "18 in communication with the atmosphere so that the air disposed below the piston 26 can be discharged to the atmosphere to prevent pneumatic damping of the downward movement of the piston. When the valve assemblies 22 and 24 are released, the cylinder 18 is moved upwardly to engage the main valve assembly 20 and close off communication between the reservoir 16 and the upper end of the interior of the cylinder l-S. When the cylinder 18 moves to a position engaging the main valve assembly 28, the exhaust valve assembly 32 is actuated to place the upper end of the interior of the cylinder 18 in comm-unication with the atmosphere. This discharges the entrap-'ped air above the piston 26 and controls the piston return valve assembly 30 so that compressed air is supplied below the piston 26, the vent assembly 42 being closed by the upward movement of the cylinder 18. The compressed air supplied by the assembly 30 retracts the piston 26 and the driving element 28 to the normal position shown in FIG. 3 to complete a cycle of operation of the tool 10.

The magazine assembly 40 for supplying the nails 34 to the drive track 36 is disposed in a novel relation to the housing 12 and is of a novel construction that permits the assembly to be economically fabricated, to supply an adequate supply of the nails 34, and to avoid any interference with operation of the tool 10. The assembly 40 is mounted on the housing 12 to form an acute angle with handle portion 12b, and the drive track 36 and the nosepiece structure 38 have a corresponding angularly offset relation to the rearwardly extending handle 12b. In addition, the magazine assembly 40 is mounted for pivoting and sliding movement relative to the housing 12 to permit the forward end of the magazine assembly to be removed from association with the nosepiece 38 so that jams in the drive track 36 may be cleared. In addition, the construction of the assembly 48 is such that a single pair of rail structures not only supports strips of the nails 34 but also encloses all of the operating components of the magazine assembly.

Referring now more specifically to the drive system embodied in the tool 10, this system. is of the same general type as that shown and described in detail in United States Patent No. 2,979,725 and in the oopending application of Richard H. Doyle, Serial No. 246,608, filed December 21, 1962, now Patent No. 3,190,187. Thisdrive system includes a pair of cylindrical portions 44 and 46 (FIG. 3) in the head portion 12a in which are slidably received two different diameter portions on the cylinder 18. The larger diameter or upper portion of the cylinder 18 is sealed by two O-rings 48 which slidably engage the cylinder 44, and a lower or smaller diameter portion of the cylinder 18 is sealed by an O-ring 50 engaging the cylindrical portion 46. An intervening space or cavity 52 defined by the O-rings 48 and 50 is selectively supplied with compressed air or connected to the atmosphere by the control valve assemblies 22 and'24. In the normal condition of the tool 10, one or both of the valve assemblies 22 and 24 supply compressed air to the space 52 which acts on the downwardly facing surfaces on the cylinder 18 Within the space 52 which are greater in area than the upwardly facing surfaces acted on by the compressed air within the reservoir 16 to provide an upwardly directed component of force biasing the open upper end of the cylinder 18 against the main valve assembly 20 to prevent communication between the upper end of the cylinder 18 and the reservoir 16.

The interior of the cylinder 18 is lined with an inner cylinder 54 preferably formed of a self-lubricating material or metal which is secured in position by a fastening means 56. The outer wall of the cylinder 54 is spaced from the inner wall of the cylinder 18 to provide an air conveying space 57 forming a part of the piston return system controlled by the piston return valve assembly 30. The piston 26 includes a greater diameter upper portion 26a carrying a pair of O-rings 58 which slidably engage the inner wall of the cylindrical insert 54. A smaller diameter lower portion of the piston 26 is adapted to engage a resilient bumper 60 disposed within a cylindrical retaining sleeve 62 which rests on the upper wall of the nosepiece structure 38, which nosepiece structure is fastened to the lower end of the head portion 12a of the housing 12 by a plurality of machine screws 64 (FIG. 1) to close the'lower end or the head portion 12a. The driver blade 28, which is secured to the piston 26, passes through an opening 66 in the resilient bumper 60 to enter the upper end of the drive track 36 formed in the nosepiece structure 38.

The venting assembly 42 for controlling the selective connection of the lower end of the interior of the cylinder 18 to the atmosphere comprises a cylindrical or annular valve element 68 that is slidably mounted in a lower cylindrical portion 70 of the head portion 12a with the interface between the cylindrical portion 70 and the sleeve 68 being sealed by an O-ring 72 carried on the sleeve 68. A compression spring 74 interposed between a flange 62a of the retaining element 62 and the lower end of the sleeve 68 normally biases a resilient O-ring 76 carried on the sleeve 68 into engagement with an inclined wall surface connecting the cylindrical portions 46 and 70 to close the lower end of the interior of the cylinder 18. However, when this cylinder moves downwardly, its lower end engages the upper end of the sleeve 68 and moves this sleeve downwardly against the element 76 out of engagement with the inclined wall.

This places the lower end of the interior of the cylinder 18 in communication with the atmosphere through one or a plurality of exhaust ports 78. When the cylinder 18 is restored to its normal position at the end of the driving stroke, the compression spring 74 slides the sleeve 68 upwardly so that the valve element 76 again engages the inclined wall surface to close communication between the lower portion of the interior of the cylinder 18 and the atmosphere.

The pistonreturn valve assembly 30 is shown and described in detail in the above-identified application of Richard H. Doyle. As set forth therein, the piston return valve assembly 30 is automatically responsive to the pressure within the upper end of the cylinder 18 or the position of the piston 26 to selectively supply compressed the valve element 80 out of engagement with the valve seat 88 so that compressed air enters the lower end of the cylinder 18 below the piston 26. This compressed air moves the piston 26 upwardly to engage the main valve 20. In this position, the port terminating the inner end of the passageway 94 is sealed by the O-rings 58. The compressed air entering through the. passageway 86 now accumulates above the piston portion 82 and overcomes the upwardly directed force due to the compressed air supplied from the reservoir 16. At this time, the exhaust valve 80 moves downwardly to engage the resilient O-ring 88 and terminates the supply of pressurized fluid to the lower end of the interior of the cylinder 18 below the piston 26. The piston 26 is retained in its upper position by the frictional engagement of the O-rings 58 with the inner wall of the cylindrical insert 54.

The main valve assembly 20 is carried on a closure cap 100 which is secured to the head portion 12a of the housing by a plurality of machine bolts 102 (FIG. 1) with a resilient sealing gasket 104 (FIG. 3) interposed between the head portion 12a and the closure cap 100 so as to close an upper end opening 106 in the head portion 12a. element 108 of a diameter slightly larger than the upper end opening in the cylinder 18. The resilient-element 108 is vulcanized or otherwise rigidly and permanently se air from the reservoir 16 to the lower end of the interior of the cylinder 18 to return the piston 26 to its normal position engaging the main valve assembly 20. The piston return valve assembly 30 is mounted in a protuberance or projection 18a on the cylinder 18 and includes a valve element 80 having a piston portion 82 slidably mounted within a two diameter cylinder for-med in the portion 18a. The upper end of the larger diameter portion of the cylinder is closed by a member 84 having a passageway 86 through which compressed air from the reservoir 16 is continuously supplied. This air acts on the piston portion 82 to provide a downwardly directed component of force that seats the valve 80 on a resilient valve element provided by an O-ring 88. This closes off communication through a passageway 90 and a port 92 between the reservoir 16 and the air conveying space-57 which is defined by the cylinder 18 and the cylindrical insert 54 and which communicates with the lower end of the interior of the piston 26.

Whenever the tool 10 is actuated to move the cylinder 18 downwardly, the piston 26 is driven downwardly to engage the bumper 60 and remains in this position when the cylinder 18 is returned to its normal position engaging the main valve assembly 20 by the release of the control valve assemblies 22 and 24. When the exhaust valve assembly 32 is operated to connect the upper end of the interior ofthe cylinder 18 to the atmosphere, the compressed air interposed between the piston portion 82 and the member 84 is largely exhausted to the atmosphere through a passageway 94, the upper end of the cylinder 18, and the exhaust valve assembly 32. The compressed air acting on the lower end of the piston portion 82 lifts cured to a plate 110 that is secured to the lower surface of the closure cap 100 by a plurality of machine screws .112. In prior constructions, the resilient element 108 of the main valve assembly has been mounted in such a manner that it can be deflected or pulled downwardly by the compressed air acting thereon when the cylinder 18 is lowered. When the cylinder 18 moved downwardly a predetermined distance, the resilient valve element previously provided snapped upwardly to provide an opening through which air was admitted to drive the piston 26. Onereason for providing this type of valve action was to permit downward movement of the cylinder 18 suflicienta more immediate response of the'tool 10 to the actuation of the control valve assemblies 22 and 24.

The exhaust valve assembly 32 is selectively responsive to the position of the cylinder 18 either to connect the upper end of the interior of this cylinder to the atmosphere, in the normal condition of the tool 10, or to close the exhaust connection whenever the tool 10 is operated. The exhaust valve assembly 32, which is completely carried on the closure cap 100, is ofiset radially from the center or axis of the cylinder 18 to permit a reduction in the overall height of the head portion 12a of the tool 10. The exhaust system controlled by the valve assembly 32 includes a vertically extending passageway 114 passing through the resilient valve element 108, the plate 110, and the closure cap in a position generally aligned with the axis of the cylinder 18. A transverse passageway 116 in the closure cap 100 connects the passageway 114 with a small diameter cylinder 118 forming a part of the housing for the control valve 32. An additional passageway 120 communicating with the atmosphere at one end is connected to the cylindrical chamber 118 by a larger diameter cylinder 122 also forming a part of the exhaust valve assembly 32.

This assembly includes a valve element 124 having an upper piston portion 124a and an intermediate valve portion 124k which are disposed within the cylinder 122.

closure 126 held in position by-a lock washer or retaining The main valve assembly 20 includes a resilient ring 128. A lower sealing portion 1240 of the member 124 is disposed within a smaller diameter cylinder 130 forming a continuation of the cylinder 118. The lower end of the valve member 124 includes an operator portion 124d which is aligned with and adapted to be engaged by the closure member 84 carried on the projecting portion 18a. The operator portion 124d does not close the passageway 86 in the closure member 84. In the normal condition of the tool 10, the lower end of the operator 124d engages the member 84 on the projecting portion 18a of the cylinder 18 to hold the exhaust valve assembly 32 in the open position illustrated in FIG. 3 in which the upper end of the interior of the cylinder 18 is connected to the atmosphere through the passageways 114 and 116, the cylinders 118 and 122, and the passageway 120.

When the tool 10 is operated so that the cylinder 18 moves downwardly, the member 84 on the projecting portion 18a moves out of engagement with the operator 124d on the exhaust valve member 124. At this time, the compressed air continuously supplied to the upper surface of the piston portion 124a from the reservoir 16 through an axially extending passageway 132 in the valve member 124 acts on the upper surface of the piston portion 124a and provides a greater downwardly directed force than the upwardly directed force resulting from the compressed air in the reservoir 16 acting on the lower surface of the sealing portion 124C. This net downwardly directed force moves the valve member 124 downwardly until a valve element provided by an O-ring 134 carried on the valve portion 124]) seats on the shoulder between the cylinders 118 and 122. This prevents communication between the passageways 116 and 120 and closes the connection between the upper end of the cylinder 18 or the reservoir 16 and the atmosphere. When the cylinder 18 is restored to the normal position shown in FIG. 3, member 84 on the the projecting portion 18a engages the lower end of the operator 124d and moves the valve member 124 upwardly against the pneumatic bias to the position illustrated in FIG. 3. In moving upwardly, the valve member 12412 lifts the O-ring 134 out of engagement with the shoulder between the cylinders 118 and 122 so that the upper end of the interior of the cylinder 18 is connected to the atmosphere over the system of passageways set forth above. This is effective through the passageway 94 to place the upper end of the piston portion 82 at or near atmospheric pressure so that the piston return valve assembly 30 operates in the manner described above. The exhaust valve assembly 32 remains in this condition until the tool 10 is next operated to lower the cylinder 18.

The safety valve assembly 22 and the manual valve assembly 24 for controlling the operation of the tool 10 are substantially the same as those described in the aboveidentified patent and application. In general, the safety valve assembly 22 includes a valve stem 140 having a notched or reduced diameter portion 140a adjacent its upper end which is slidably received within a sleeve 142 carried on the housing 12. The lower end of the valve stem 140 is connected to a collar 144 so that a compression spring 146 interposed between a projection 148 on the head portion 12a and the collar 144 biases the valve stem 140 to the position shown in FIG. 3 in which compressed air from the reservoir 16 flows into the space 52 through a passageway or port 150. The collar 144 is also connected to a wire operator element 152 (FIGS. 1, 4, and 5) that is slidably mounted in a groove 153 in the nosepiece structure 38. The lower end of the operator element 152 projects below the lower end of the nosepiece structure 38 and is adapted to engage a workpiece. Thus, when the tool 10 is moved into engagement with the workpiece, the operator 152 is moved upwardly to produce a corresponding movement of the valve stem 140 against the action-of the compression spring 146. When the valve sternv 140 moves upwardly, the upper end of the stem closes otf direct communication between the passageway 150 and the reservoir 16, and the notched or recessed portion a moves into alignment with a passageway 154. The passageway 154 communicates with the manually controlled valve assembly 24 which includes a ball valve element 155 and a passageway 156 communicating with the reservoir 16. Thus, compressed air from the reservoir 16 normally passes through the passageways 156, 154, and to the space 52.

When the manual valve assembly 24 is actuated by pivoting a trigger'157 in a counterclockwise direction about a pivot pin 158, a fluted valve stem 159 moves upwardly to seat the ball valve in a position closing the port terminating the passageway 156. This movement of the ball valve 155 also places the passageway 154 in communication with the atmosphere through the flutes along the stem of the operator pin 159. Thus, the space 52 is placed at atmospheric pressure, and the compressed air within the reservoir 16 acting on the upwardly facing surfaces of the cylinder 18 produces a downwardly directed force which moves the cylinder 18 downwardly to cause the sequential operation of the valve assemblies 32 and 42 in the manner described above. When both or either of the valve assemblies 22 and 24 is released, compressed air from the reservoir 16 enters the space 52 through the passageway 150 or through the passageways 156, 154, and 150 to provide an upwardly directed force acting on the cylinder 18 to move it upwardly into engagement with the main valve assembly 20. This closes the valve assembly 42, opens the valve assembly 32, and causes the operation of the piston return valve assembly 30 for the period of time necessary to return the piston 26 and the driver blade 28 to their normal positions.

The magazine assembly 40 (FIGS. 1, 2, and 4-7) for feeding individual nails 34 from a strip thereof into the drive track 36 in the nosepiece structure 38 is of an easily and economically fabricated construction in which a pair of side rails 160 and 162 not only provides supporting rails for the nails 34 but also provides a complete housing for the magazine 40, including a housing or enclosing means for the actuating means for this assembly. Each of the rails 160 and 162 includes upper and lower parallel wall sections 160a, 162a, and 160b, 162b, respectively, joined by an outwardly projecting generally U-shaped section 160a, 1620. The rails 160 and 162 are secured in opposed generally parallel positions so that the upper wall sections 160a, 162a and the lower wall sections 160b, 162b define a generally vertically extending slot 164 for receiving the shanks of the nails 34 with the heads thereof slidably engaging the upper edges of the wall sections 160a and 162a. The lower ends of the wall sections 16% and 1621: can be joined by a plurality of spaced fasteners or rivets 166 (FIGS. 1 and 4) with a spacer 167 interposed therebetween. Adjacent the forward end of the magazine assembly 40, a cover member 168 of a configuration corresponding to that of the rail 162 is secured in a parallel contiguous position. The cover 168 includes a lip or flange portion 168a (FIG. 6) overlying the upper edges of the rails 160 and 162 to provide a cover over the heads of the nails 34 to maintain these nails in proper position on these rails.

The rear end of the strip of nails 34 is engaged by a pusher indicated generally as 170 (FIGS. 4-6) which comprises a pair of plates 172 and 174 spot-welded together in a face-to-face relation to provide a unitary structure. The upper edges of the plates 172 and 174 are provided with oppositely extending flange portions 172a and 174a which rest on the upper edges of the side walls 162a and 160a, respectively, of the rails 162 and 160 to provide means for slidably mounting the pusher 170 within the slot 164. The trailing or rear edge of the plate 172 is also provided with a downwardly turned portion terminating in a lug 172]) by which the pusher 170 can be manually apprehended and retracted to permit a strip of nails 34 to be placed in the slot 164. Since the upper and lower portion of the pusher 170 are received within the portions of the slot 164 formed by the upper walls 160a, 162a and the lower Walls 160b, 16211, the pusher 170 cannot be tipped or canted.

To provide means for resiliently urging the pusher 170 against a strip of nails 34, a resilient biasing means is provided comprising a drum 176 to which the inner end of a coiled fiat spring or negator 17 8 is secured. The other end of the spring 178 is secured to a fastener 180 which is provided with enlarged end portions and which is receceived Within a slot 182 in the rear edges of the plates 172 and 174 forming the pusher 170.

The coiled portion of the negator or spirng 178 and the supporting drum 176 therefor are pivotally mounted within a housing adjacent the forward end of the magazine assembly 40 by a shaft 184. The housing is formed by splitting the vertically extending wall of the wall section 160a and forming the free ends thereof into two walls 160d (FIGS. and 6) that extend outwardly parallel to each other. A generally U-shaped housing member 186 is nested with the falls 160a' and includes two flanged portions 186a and 186b (FIG. 6) which are moved into abutting parallel relationship with the wall sections 160a and 160b, respectively, on the rail 160. The shaft 184 passes through aligned openings in the walls 160d and the housing 186 to pivotally mount the drum 176 and the coiled portion of the fiat spring negator within the housing formed thereby.

The magazine assembly 40 is slidably connected at its forward end to the nosepiece structure 38 and is connected at a point spaced rearwardly from the forward portion to the rear of the handle portion 12b of the housing for both sliding and pivoting movement to permit the connection between the forward end of the magazine assembly 40 and the nose piece structure 38 to be opened. This is useful in clearing jams in the drive track 36. Further, since the strips of nails 34 are formed with the heads of successive nails spaced above each other, the magazine assembly 40 inclines upwardly from its point of connection to the nose piece structure 38 toward its point of interconnection with the handle 1212.

To accomplish this, the forward ends of the vertically extending walls 160a, 162a, 160b, and 162b of the rails 160 and 162 and the corresponding vertically extending wall portions of the elements 168 and 186 are cut along a bias or taper. When the forward end of the magazine assembly 40 is moved into engagement with a fiat vertically extending wall 38a (FIG. 4) at the rear of the nosepiece structure 38, the magazine assembly 40 forms an acute angle with the nosepiece structure 38 and extends upwardly and rearwardly toward the rear of the tool 10. The lower forward end of the walls 16% and 162b are each provided with a forwardly extending lug, such as a lug 162d illustrated in FIG. 4, which is received within one of two recesses 38b in the nosepiece structure 38 to aid in locating the nosepiece structure 38 and the magazine assembly 40 relative to each other. In this position, the slot 164 defined by the magazine assembly 40 and thus, the pusher 170 is aligned with a rearward open slot 190 (FIGS. 4 and 5) in the nosepiece structure 38 through which individual nails 34 are fed into the drive track 36. The slot 190 includes a transversely enlarged upper portion through which the heads of the nails 34 are fed and a narrower lower portion adapted to pass only the shank portion of the nails. This permits the forward portion of the pusher 170 to enter the slot 190 to feed the last nail 34 in the strip into the drive track 36.

If no nails are provided in the magazine 40 and if the pusher 170 is advertently released following any substantial elongation of the spring 178, the forward end of the pusher 170 can enter the drive track 36 through the slot 190 with the result that the forward end of-the pusher will impinge on the hardened steel forming the drive track.

i This is likely to result in damage to the pusher,'as by swaging the forward end thereof. In order to prevent any possible damage to either the walls of the drive track 36 or the forward end of the pusher 170, this pusher is provided with a bumper or resilient cushioning means. The cushioning means comprises a compression spring 192 disposed within an opening 194 in the two plates 172 and 174 forming the pusher 170. The opening 194 includes a pair of tabs projecting into its opposite ends to retain the compression spring 192 in position. Accordingly, if the pusher 170 is released with the spring 178 extended and with no nails 34 in the magazine assembly 40, the pusher 170 is propelled forwardly by the resilient bias until such time as the leading convolution of the compression spring 192 strikes the wall surface 38a on the nosepiece structure- 38. This compresses the spring 192 not only to prevent engagement between the forward end of the pusher 170 and the wall of the drive track 36 but also to cushion the termination of movement of the pusher 170.

To provide means for slidably and detachably mounting the forward end of the magazine assembly 40 on the nosepiece structure 38, the forward portions of the vertically extending walls on the wall sections 1600, 162a and the adjacent portions 168s and 186c on the housings 168 and 186 are formed as tabs or' lugs which are slidably received within two inclined and aligned slots 196 (FIGS. 1, 4, and 5) formed in the opposite side walls of the nosepiece structure 38. These tabs are also formed with forwardly open slots 198 in which are slidably received two machine screws 200 which are threaded into the nosepiece structure 38. By loosening the machine screws 200,.it is possible to slide the forward end of the magazine assembly 40 into and out of an assembled relation with the nosepiece structure 38.

A 'rear portion of the magazine assembly 40 is mounted on the rear end of the handle portion 12b of the housing for sliding and pivoting movement. More specifically, the vertical wall of the section 162a of the rail 162 is provided with an elongated slot 202 (FIGS. 1 and 7) in which is received a shoulder formed on a machine screw 204 that is threaded into the handle 12b. An opening 206 is also formed in the vertical Wall of the section 1600 of the rail alignedwith the head of the machine screw 204 when the magazine assembly 40 is in its normal assembled position. By inserting an instrument through the opening 206, the head of the machine screw 204 can be reached'to permit it to be loosened. When the machine screw 204 is loosened together with the machine screws 200, the magazine assembly 40 can be moved rearwardly until the lugs at the forward end of the magazine assembly 40 are displaced from the slots 196. The forward end of the magazine assembly 40 'can then be pivoted downwardly to the position shown in dot-and-dash outline in FIG. 1. This permits access to the opening or slot in the nosepiece structure 38 to permit a jammed nail 34 to be removed. It also permits access to the forward portion of the magazine. assembly 40.

When this assembly is to be restored to its assembled position with the nosepiece 38, the magazine 40 is pivoted around the machine screw 204 in a clockwise direction from the position shown in dot-and-dash outline in FIG. 1 to a position in which the forwardly projecting lugs at the forward end of the magazine assembly 40 are aligned with the slots 196 in the nosepiece structure 38. The magazine assembly 40 is then moved forwardly until the machine screw 204 engages the rear end of the slot 202 and the machine screws v200 are received within the slots 198. The machine screws 200 and 204 are then tightened to positively secure the magazine 40 in its proper assembled relation.

-In order to increase the storage capacity of the magazine 40, it is desirable to have this magazine extend rearwardly beyond the back edge of the handle portion 12b of the housing 12 for the tool 10. To permit this, the

magazine assembly 40, as well as the nosepiece structure 38, are secured to the housing 12 for the tool 10 in a manner such that these elements form an acute angle with the rearwardly extending handle 12b when viewed from the top of the tool 10 FIG. 2). Although the tool 10 is illustrated as being adapted to drive nails 34 having a full round head so that a round driving element 28 could be provided, it is frequently desirable to use a somewhat flattened or transversely elongated driver element 28 so that the heads of adjacent nails in the strip can be overlapped to permit a greater number of nails to be stored in a strip of a given length. Since any flattening of the driver blade 28 prevents the symmetry possible with round driver elements and round drive tracks, it is necessary or desirable to provide a guiding means engaging the blade 28 to insure proper orientation of the blade within the drive track 36. Accordingly, the drive track 36 illustrated in the drawings includes a rounded central portion 36a (FIG. for receiving the central portion of the driver element 28 and two opposed and generally rectangular extensions 36b for receiving guiding structures on the element 28. The guiding recesses 36b are disposed normal to a horizontal projection of the line along which the nails 34 are fed into the drive track 36. Since the center line or longitudinal axis of the magazine 40 defined by the slot 164 is normal to a line connecting the guiding recesses 36b and forms an acute angle with the rearwardly extending handle 1212, the nosepiece structure 38 must also be angularly displace-d about the axis of the cylinder or relative to the head portion 12a of the housing 12 so that a line or plane connecting the recesses 36b also intersects a line or plane passing through the handle 1212 at an acute angle. This is demonstrated by the dot-and-dash illustration of the nosepiece structure 38 in FIG. 2 of the drawings. Since the line or plane connecting the guide recesses 36% in the drive track 36 is not normal to a line or plane passing along the longitudinal axis of the handle portion 1%, the plane of the transversely elongated driving element 28 also is not normal to this line or plane but forms an acute angle therewith.

Although the present invention has been described with reference to a single illustrative embodiment thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this invention.

What is claimed and desired to be secured by Letters Patent of the United States is:

1. A fastener driving tool comprising a housing including a movable piston actuated fastener driving element, a nosepiece structure carried on the housing and having a drive track for slidably receiving the driving element, a magazine assembly for feeding fasteners into the drive track, said magazine assembly including a pair of spaced projecting portions at its forward end between which the nosepiece structure is slidably received, mounting means spaced rearwardly from the projecting portions and connected between the housing and the magazine assembly for mounting the magazine assembly for sliding and pivoting movement relative to thehousing, [and securing means connected between the nosepiece structure and the projecting portions for detachably connecting the projecting portions to the nosepiece structure to permit the magazine assembly to be retracted from the nosepiece structure and pivoted downwardly away from the nosepiece structure.

2. The fastener driving apparatus set forth in claim 1 in which the housing includes a rearwardly extending handle portion, in which the mounting means is carried on the rearwardly extending handle portion, and in which the mounting means and the securing means mount the magazine assembly on the housing with the magazine assembly extending outwardly away from the handle portion to define an acute angle therebctween.

3. A fastener driving apparatus comprising a housing having a cylinder, a piston actuated fastener driving element movable within the cylinder, said housing having a lower portion forming a drive track in which the driving element is movably mounted, a magazine assembly for supplying fasteners to the drive track, first structure on the forward end of the magazine assembly engaging the lower portion of the housing to slidably mount the forward end of the magazine assembly on the housing, and second structure on the magazine assembly engaging the housing and located rearwardly on the magazine assembly from the first structure for mounting the magazine assembly for sliding and pivoting movement relative to the housing, whereby the forward end of the magazine assembly can be slidably separated from the housing and pivoted downwardly away from the housing.

4. In a fastener driving apparatus, a housing containing a movable fastener driving element, a nosepiece forming a drive track in which the driving element is movable, a magazine assembly for feeding fasteners into the drive track, said nosepiece having an opening through which fasteners can be fed from the magazine assembly into the drive track, pusher means movably mounted in the magazine assembly and resiliently biased for movement to Ward the opening, and resilient bumper means carried on the pusher means and adapted to engage said nosepiece adjacent the opening to provide resilient means for terrninating movement of the pusher means and for preventing movement of the pusher means into the drive track.

5. In a fastener driving apparatus of the type having a nosepiece with a drive track for receiving a driver element and an opening into the drive track, a magazine housing including structures forming a groove adapted to receive a strip of fasteners, said housing being mounted adjacent the nosepiece with the groove aligned with the opening to feed fasteners into the drive track, pusher means slidable in the groove, first resilient means acting on the pusher means to bias the pusher means toward the opening, a stop structure mounted on the apparatus in a fixed position relative to the opening, and second resilient means carried on the pusher means and movable 1nto engagement with the stop structure for resiliently arresting movement of the pusher means to prevent the pusher means from entering the drive track.

6. The fastener driving apparatus set forth in claim 5 in which the pusher means defines an aperture and in which the second resilient means includes a compression spring mounted in the aperture.

7. In a fastener driving apparatus of the type having a nosepiece forming a drive track for receiving a fastener driving element and an elongated fastener having a transverse head, a pair of fastener supporting rails mounted in spaced parallel positions to form a slot for receiving the elongated fasteners with their heads resting on the upper edges of the rails, the side wall of one of the rails being formed with an outwardly projecting enclosed portion extending along its length, pusher means disposed in the .slot and slidably mounted on said upper edges of the rails, resilient means for biasing the pusher to feed the fasteners into the drive track, said resilient means being disposed in the outwardly projecting enclosed portion on the one side wall, a stop structure mounted on the apparatus in a fixed position, said pusher means having an opening, and resilient bumper means carried in the opening for engaging the stop structure to cushion the termination of movement of the pusher means.

8. In a fastener driving apparatus of the type'having a nosepiece forming a drive track for receiving a fastener driving element and an elongated fastener having a transverse head, and a depending portion, a pair of fastener supporting rails mounted in spaced parallel positions to form a slot for receiving the elongated fasteners with their heads resting on the upper edges of the rails, the side walls of the rails having oppositely extending and outwardly projecting portions between their upper and lower edges forming an enlarged cavity, the cavity separating the slot into upper and lower portions, spaced portions of the depending portion of the fastener being received in the upper and lower portions of the slot, pusher means disposed within the cavity and including parts disposed in the upper and lower portions of the slot, and resilient biasing means connected between the pusher means and the rails and disposed substantially completely within the elongated cavity.

9. The fastener driving apparatus set forth in claim 8 in which the resilient biasing means includes flat spring means connected at one end to the pusher means and being formed in a coil at its other end, said coil being mounted for rotation about a fixed axis and being disposed within an enlarged portion in part of the cavity formed by one of the rails.

10. In a fastener driving apparatus of the type having structure defining a drive .track for receiving fasteners having an elongated shank and a transverse head, a pair of fastener supporting rails mounted in spaced and parallel arrangement, said rails having generally parallel upper and lower edge portions defining upper and lower slots and outwardly projecting intermediate portions defining a cavity, said fasteners being disposed with their heads resting on the upper edge of the rails and with their shanks disposed in the upper and lower slots and extending through the cavity, pusher means slidably mounted on the rails and including portions disposed in the upper'and lower slots, and resilient means for biasing the pusher means against the fasteners to feed the fasteners into the drive track, said resilient means being connected between the pusher means and the rails and being disposed in the cavity.

References Cited by the Examiner UNITED STATES PATENTS 2,733,440 2/1956 Jenny 227-123 2,801,415 8/1957 Jenny 227-123 X 3,056,137 10/1962 Wandel et al. 13.1 3,058,114 10/1962 Haubold 1-3.1 3,086,207 4/1963 Lingle et al. 227130 3,094,900 6/1963 Wandel et a1. 91--423 3,106,134 10/1963 Osborne 91-189 FOREIGN PATENTS 847,388 9/1860 Great Britain.

FRANK E.'BAILEY, Primary Examiner.

GRANVILLE Y. CUSTER, JR., Examiner. 

1. A FASTENER DRIVING TOOL COMPRISING A HOUSING INCLUDING A MOVABLE PISTON ACTUATED FASTENER DRIVING ELEMENT, A NOSEPIECE STRUCTURE CARRIED ON THE HOUSING AND HAVING A DRIVE TRACK FOR SLIDABLY RECEIVING THE DRIVING ELEMENT, A MAGAZINE ASSEMBLY FOR FEEDING FASTENERS INTO THE DRIVE TRACK, SAID MAGAZINE ASSEMBLY INCLUDING A PAIR OF SPACED PROJECTING PORTIONS AT ITS FORWARD END BETWEEN WHICH THE NOSEPIECE STRUCTURE IS SLIDABLY RECEIVED, MOUNTING MEANS SPACED REARWARDLY FROM THE PROJECTING PORTIONS AND CONNECTED BETWEEN THE HOUSING AND THE MAGAZINE ASSEMBLY FOR MOUNTING THE MAGAZINE ASSEMBLY FOR SLIDING AND PIVOTING MOVEMENT RELATIVE TO THE HOUSING, 